Pencil and method of producing same



Mwdh 13.@9 QE F, Q DELl 1 PENCIL AND METHOD oF PRODUCING SAME Fild'April l2, 1933 4 I N1 m ,N

Patented Mar. 10, 1936 mural) STATES PATENT OFFICE Frank C. Deli,Chicago, Ill., assigner to Autopoint Company, Chicago, Ill., acorporation of Illinois Application April 12, 1933, Serial No. 665,730

6 Claims.

My invention relates to pencils and particularly to a novel method ofconstruction resulting in economy in cost of production and greaterstrength and rigidity in operation.

It has been found to be desirable in automatic pencil construction toprovide a tapered portion consisting largely oi non-metallic material inorder to avoid slipperiness and to enable holding the pencil withoutfatigue. However, a part of the tip must be made of metal in order toprovide the requisite strength. I have made a combination of metal andnon-metallic parts and so designed the construction that it may be madeby a series of steps in which the final structure has many advantages.

The pencil and the method of producing the parts will be more readilyunderstood by reference to the accompanying drawing, in which:

Fig. l is a somewhat enlarged longitudinal n'sectional view through apencil constructed in accordance with my invention;

Fig. 2 is a sectional view through the metal tube or cartridge before ithas been shaped.

Fig. 3 is a similar view showing the tip after 'the first swedgingoperation.

Fig. 4 is a view of two telescoped tubes that are assembled as shown inFig. 5, that figure showing the next operation, in which the cylindricalpart is swedged onto the tubes.

' Fig. 6 shows the next operation in whichthe closed, tapered end hasbeen cut off, the said end slitted, a transverse or diagonal notch cutin the cylindrical portion and tube, and a friction wing cut in thetube;-

Fig. 7 is a sectional view through the construction of Fig. 6;

Figs. 8 and 9 are views similar to Fig. 1 showing two modified forms oithe pencil construction and,

Fig. l is a sectional view on the line Ill-I0 of Fig. 6.

In the drawing I show in Fig. 1 a pencil body i@ having a reduced lowerend Il, one part l2 of which is cylindrical and another part I3 istapered. The body has an axial opening I4 therein of roundcross-section.

The tip portion to which this invention relates consists of two parts, atapered non-metallic portion l5 having a recess I6 therein shaped to tthe -reduced portion H, and a metallic portion l 'l the exposed part ofwhich is also tapered. The tapered metallic portion terminates in ashoulder I3 at the junction with the round cylindrical portion ls.Contained within the tip is -=a plain tube 20 and a threaded tube 2|telescoped therein. A transverse inclined notch 22` is cut through thecylindrical portion and the tube 20 and the non-metallic tip portion Ilis molded in place, the material flowing into the notch 22 to provide ananchor. A plunger 23 5 having projections engaging the threaded tubeserves to propel a lead indicated at 24 through the opening in the lowerextremity of the tapered metal portion H. It will be noted that themetal at the point 25 of the tip is of thicker 10 cross-section than theremainder of the tip. The manner of obtaining this result will bedescribed hereafter. The operation of the pencil is simple and need notbe described in detail except to say that the plunger has a non-circularportion that slides within a non-circular recess formed in the part 26of the pencil body, the lead being ejected by rotating the tip relativeto the body.

In the construction of Fig. 8 the pencil body l is the same and theconstruction of the tip is substantially the same as that alreadydescribed except that the threaded tube 2l is directly anchored into themetal tip portion Without the tube 2i! shown in Fig. 1. The operationsof manufacture are the same with the exception noted.

In the construction of Fig. 9 the pencil body likewise remains the sameand the tip construction is identical except that the tube 28 isthreaded only at the upper end, said upper end 30 29 being swedgedslightly to reduce the diameter and interiorly threaded at the reducedportion. This-entails a smaller or finer thread in the part 'Z9 and onthe plunger 3) instead of the large rolled threads shown in thepreceding illustrations. Otherwise the tip construction is the same.

Certain structural characteristics of a pencil body and tip give rise tothe necessity for the production of the tip in the manner hereinafter 40described. For example, it would seem, without knowledge of the actualfacts, that the tapered metalic portion of the tip and the tube 2t,might readily be formed of one piece and thus .avoid the operations thatare required to asthe sleeve 20 is, for practical purposes, out of thequestion. However, the tapered metalic portion I1, must be composed ofrelatively heavy metal, first, in order to provide adequate strength atthe slitted end, and second, to enable the swedging of a relatively deepand sharp shoulder I8 at the point where the non-metalic molded materialjoins the metal portion I1. This could not be secured in a thin metalconstruction. For this reason, a part, such as shown at 2|,

is provided, the walls of which are of increasingA thickness from theopen to the closed end. By the swedging operation described, the epenend is reduced in diameter, thereby thickening the walls and providingthe adequate material at the point described.

The method of production of the tip portion is illustrated in Figs. 2 to7 inclusive. The metal tip part is formed from a tube 3| having a closedend, the thickness of the metal of the tube increasing from the open tothe closed end as best shown in Fig. 2 the showing being exaggerated. Ofcourse, a tube open at both ends may be used, the wall thickness beingprogressively greater toward the end that is to be the small end of thetaper. However, I prefer to use the closed tube as shown. In the nextoperation the round tube is located within the part shown in Fig. 3 andthereafter the cylindrical part 32 is swedged to reduce its diameter andthe tube 20 is very slightly compressed as shown in Fig. 5 forming amechanical bond between the parts. In the next operation as shown inFig. 6 the pointed closed end is cut off to leave a lead opening, slits33 are provided in the said end, a transverse notch 22\ is provided inthe cylindrical part, and the wing 34 is cut in the tube 20. After theslitting operation a `further swedging operation is performed on theslit end to close the slits and insure a round lead opening. Thethreaded tube 2| is then placed within the tube 20 and an additionalswedging operation performed to hold the tubes in proper position untilthe next operation is completed, that is the molding of the tip inplace. The non-metallic tip part I5 is then molded in the positionshown, providing a'uniform taper practically from end to end of the tip,the molding material being pressed into the notch 22 to insure a bondbetween the metallic and non-metallic parts and to anchor the spiraltube in place. It will be understood that while we have spoken ofswedging'operations in changing the shapes, the same result may besecured by other machine operations.

The function of the wing 34 is to insure a substantially uniformfriction between the tip and the body. Thus it is not necessary'to'relyon varying frictional contact between the reduced lower end of the bodyand the tapered recess in the tip.

The advantage in the type of tip construction shown is that a stiff andpermanent lead-gripping point may be made without the use of excessivelythick material'in the remainder of the tip. The greater wall thicknessof the part 3| at the closed end insures additional wall thickness ofthe slit end through which the lead projects.

It is obvious that the construction may be utilized in othermodifications than those shown and I do not wish to be limited except asindicated in the appended claims.

VI claim:

1. The method of making pencils which consists in providing a relativelyshort tube having one end closed, then swedgin`g the closed end toprovide a taper therein, thereby somewhat elongating the tube, thenpositioning an elongated tube axially within the swedged member, thenswedging the cylindrical portion of the member into close contact withthe exterior of the elongated'tube, then cutting off the closed taperedend and providing longitudinal slits in said tapered end, and thenforming a nonmetallic moldable material over the swedged cylindricalportion of the assembly in order to provide a complete tip portion for apencil.

2. The method of forming pencil tips with attached lead feedingmechanism consisting of the. steps of swedging the closed end of acylinder to provide a tapered portion and a cylindrical portion, thenswedging the cylindrical portion over a threaded tube, then cutting offthe closed tapered end, slitting said end and providing a transversenotch in the swedged cylindrical portion, then molding a non-metallicmaterial over said swedged portion, the material entering the notchtherein.

3. The method of forming pencil tips having an attached lead projectingmechanism, consistingfof swedging a cylinder having a closed end toprovide a tapered portion on the closed end and a cylindrical portion ofa diameter less than the largest diameter of the tapered portion,

the swedging operation by which the cylindrical portion is formedserving to confine a tube within said cylindrical portion, then cuttingoi and slitting the extreme end of the tapered portion, then providing atransverse notch in the cylindrical portion, then molding a tip portionover said cylindrical portion and forcing a quantity of the materialinto the notch.

4. In a pencil tip, the lower end of which is tapered and the upper endof which is cylindrical and 'of less diameter than the large diameter ofthe tapered portion, a threaded tube anchored within said cylindricalportion, registering notches being provided in the cylindrical portionand'said'tube, anon-metallic tip portion being overy said cylindricalportion and projecting into said notch and shaped to correspond to theAtaper of the metal tip portion.

5. In combination, a pencil tip consisting of metallic and'non-metallicportions, the metal portion consisting of an element having a taperedlower end, the lead outlet end being of greater Wall thickness than theremaining portion,v the element having a cylindrical portion of lessdiameter than the largest diameter of the tapered portion, a :tubeconfined within the cylindrical portion, the cylindrical portion andtube having a registering transverse notch, the non-metallic portion ofthe tip being formed over the cylindrical portion and projecting intothe notch therein.`

6. In combination, a pencil tip consisting of metallic and non-metallicportions, the metal portion consisting of an element having a taperedlower end, the leadoutlet end being of greater wall thickness thantheremaining portion, the element having a cylindrical portion of lessdiameter than the largest diameter of the tapered portion, a tubeconfined within the cylindrical portion, the cylindrical portion andtube having a registering transverse notch, the non-metallic portion ofthe tip being formed over the cylindrical portion and projecting intothe notch therein.

FRANK C. DELI.

